WEDNESDAY PUZZLE — Today’s puzzle is the debut crossword of Brian Cox. I suspect we’ll be seeing more of him.

Today’s Theme

Today’s theme is “Knock-knock jokes.” These are the apex of literature for 5-year-olds, as well as all of us who have never grown up. The theme is a little tricky because you have to supply your own “ ... who?” For instance, we have “Knock knock” and WHO’S THERE provided by 17-Across. Then we have our first example, “Esther ... ,” at 21-Across. Now we get to add our own “Esther who?” so the entry, ANYONE HOME?, makes sense. Get it? Esther (“is there”) anyone home? If you’re properly channeling your inner 5-year-old, you’re rolling on the floor now. It just happens that the famous authority on 5-year-olds of all ages, Deb Amlen, has written on this very topic for Ravishly.

I’ll let you discover the rest of Brian’s gems.

Tricky Clues

■ 9A: As you might guess, FAKIR is an Arabic word. The original fakirs were Muslim mendicants. But the term is also used for Hindu and Buddhist ascetics who survive on alms.

■ 14A: Did you think of elk or chipmunks first? I did. I have a picture somewhere of a chipmunk in Yellowstone with his nose pressed up against the lens. They’re very tame and there sure seem to be millions of them. But the correct answer is ACRES.

■ 39A: Did you know that both Natalie Portman and Gene Simmons were born in Israel? His real name is Chaim Witz.

■ 47A: “Like all prime numbers but one.” The one is two, and it’s not ODD.

■ 49A: SLR, single-lens reflex camera, is one of those must-knows for crosswords.

■ 18D: HAIR metal was originally a put-down of glam rock bands who seemed to concentrate more on their coifs than their chords. But the bands took to the term. The epitome of hair metal was probably the crossword fave, Mötley Crüe.

■ 22D: NIGEL Farage, the “Brexit” leader, is probably better known to Americans for his support of President Trump.

■ 26D: Is this SWAMP clue part of a mini-theme? Along with ...

■ 51D: PENCE. Or am I being a snowflake?

■ 29D: The question mark in “Overcollect?” warns you that we’re not talking about charging too much. That’s called misdirection and it starts in earnest on Wednesday. HOARDers definitely overcollect. My dad had a Ph.D. in hoarding.

■ 63D: “Play HOB with,” sounds British, doesn’t it? But it’s American in origin. “Hob” is a euphemism for “hell,” being short for “hobgoblin.” Goblins have personalities. Only the mischievous ones are hobgoblins.

Now lets hear from Mr. Cox, who is taking his New York Times debut very calmly.

Constructor Notes

This is my first published crossword so I’m a bit out of my mind with excitement. I can’t stop grinning or doing little dance moves when I think no one is watching.

I should admit right up front that I am not Brian Cox the physicist. Or the actor. Or the former Chicago Bears linebacker, who spells his name differently anyhow.

I am a newspaper editor in Detroit. I have had some mystery short stories published in Alfred Hitchcock’s Mystery Magazine, where I was once the managing editor many, many years ago. I recently had my first play, “Clutter,” produced at Theatre Nova in Ann Arbor, and I am the artistic director of a small theater company called Pencilpoint Theatreworks here in Ypsilanti. Ann Arbor constructors James Tuttle and Peter Collins are local celebrities in my mind.

My puzzle went through three revisions over the course of a year. Will was incredibly patient with me as I worked through refining the theme answers and the fill. This was the sixth puzzle I had submitted for Will’s consideration. I am the tortoise of constructors. The theme came to me as I was recalling days when my son was very young and he went through a period when he was delighted with “Knock Knock” jokes. We would spend time before bed making different ones up. I thought combining knock-knock jokes with a crossword would make an interesting hybrid. One theme answer that didn’t work for Will that I thought was pretty funny was the classic, “Hutch who?” with the response being “gesundheit.” He wanted the responses to be complete sentences, which is the better idea, but I shed a few tears letting “gesundheit” go.